Spring assembly for spring cushions



March 15, 1960 Y J. G. PLATT 2,928,458

SPRING ASSEMBLY FOR SPRING CUSHIONS Filed 001:. 7, 1957 INVENTOR John 6. F/aff AI/or/My.

United States Patent SPRING ASSEMBLY FOR SPRING CUSHIDNS John G. Platt, Carthage, Mo., assignor to Flex-o-Lators, Inc., Carthage, Mo.,a corporation of Missouri Application October 7, 1957, Serial No. 688,527 4 Claims. (Cl. 155-179) This invention relates to new and useful improvements in spring assemblies for spring cushions, and has particular reference to spring assemblies of the type comprising a series 'of substantially planar spring units disposed in spaced apart vertical planes and each connected to a furniture frame only at its opposite ends.

This type of spring assembly has distinct advantages in that the units may be placed fiat in a very compact package for storage, handling and shipping, thus overcoming the well-known disadvantage that such assemblies are usually extremely bulky in proportion to their weight, and are hence difficult to store and expensive to ship. They are also quite simple and economical to install, and do not require specially fabricated or complicated furniture frames to accommodate their use.

On the other hand, spring assemblies of the type described have to my knowledge been subject to a serious disadvantage in that since the individual spring units are each secured to the frame only at their ends, without intermediate supports, the span of said units are quite large, and difliculty is therefore experienced in providing desirable characteristics of yieldability. For example, such assemblies have a tendency to sag objectionably in the central portion thereof when a full load is applied thereto. Attempts to reinforce the central span portion of the spring units, in order to prevent this sagging and to preserve a neat appearance, have resulted in an assembly which is objectionably hard. or stiff when, for instance in a cushioned chair, a person first applies his weight thereto.

The principal object of the present invention is, therefore, the provision of a spring assembly of the general character described which overcomes the objectionable features above discussed, which provides the desired softness or yieldability when weight is first applied thereto, but wherein the stiffness is gradually increased as the weight applied increases, in order to prevent undue sagging and to preserve a neat, tailored appearance.-

Generally, this object is accomplished by forming each spring unit as a compound member comprising two separate springs, these two springs being so related that substantially only one of the springs is eifective during the initial deflection of the assembly, the other of said springs being gradually brought into play to reinforce the first as the deflection increases.

Other objects are simplicity and economy of construction, efficiency and dependability of operation, and adaptability for use in a wide variety of types of furniture, and for other purposes.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the drawing, wherein:

Fig. 1 is a top plan view of a spring assembly embodying the present invention,

Fig. 2 is a sectional view taken on line 11-11 of Fig. 1, with portions broken away, and

Fig. 3 is an enlarged sectional view taken on line IIIIII of Fig. 2.

Patented Mar. 15, 1960 I Like reference numerals apply to similar parts through; out the several views, and the numeral 2 applies to a is of rectangular form, comprising a front rail 4, back rail 6, and parallel side rails 8, all rigidly joined together. Secured to said frame are a plurality of compound spring units 10 disposed in parallel vertical planes spaced regularly across the width of the frame. Each of said spring units comprises a main spring 12 and an auxiliary spring 14, both formed of flat strips of spring steel or other suitable material.

Main spring 12 comprises a substantially straight central portion 16 which is disposed above and approximately parallel to the plane of the frame, and which in conjunction with the like portions of the other units forms the load-supporting platform of the assembly. At each end of said central portion, spring 12 is bent to form an inwardly converging V-formatio'n, having an inwardly and downwardly inclined leg 18 connected to central portion 16 by bend 20, and an outwardly extending substantially horizontalleg 22 connected to the lower end of leg 18 by bend 24. Legs 22 extend respectively over the upper surfaces of front and rear frame rails 4 and 6, and'are each provided with a terminal leg 26 bent downwardly to overlap the outer surfaces of said rails.

Auxiliary spring 14 is shaped somewhat similarly to the, main spring. It comprises a central portion 28 which is bowed slightly to an upwardly convex form, and which is fixed at its mid-portion to the mid-portion of central portion 16 of the main spring by rivet 30. ,Normally, portion 28 of the auxilliary spring contacts :portion 16 of the main spring only directly adjacent said rivet, the end portions of portion 28 curving gradually downwardly from portion 16. At each end of portion 28, which is substantially shorter than the corresponding portion 16 of the main spring, the auxiliary spring is provided with an inwardly and downwardly inclined leg 32 which lies against the corresponding leg 18 of the main spring and is connected thereto by a rivet 34, and an outwardly extending approximately horizontal leg 36 lying against the corresponding leg 22 of the main spring'and fixed thereto by rivet 38. Legs 32 and 36 of the auxiliary spring are connected by a bend 40 which lies against the bend 24 of the main spring. Legs 32 of the auxiliary fasteners which extend through both the main and-auxiliary springs and are anchored in said rails. All of spring units 10 are interconnected and stabilized against movement transverse to their planes by a plurality of flexible steel tie strips 48 extending transversely across the load-supporting platform of the assembly, each of said strips being secured to the central portion 16 of each main spring at its point of intersection therewith by a suitable fastener such as rivet 50., The illustration shows two such tie strips disposed respectively at the forward and rearward edges of the load-supporting platform, although it will be evident that any desired number .of'ties could be used. It will of course be understood that the assembly shown is in use covered by suitable layers of padding and upholstery. 

